The present invention relates to the field of mining machines. Specifically, the present invention relates to a dipper door and a dipper door trip assembly on a mining machine, such as a rope shovel.
Industrial mining machines, such as electric rope or power shovels, draglines, etc., are used to execute digging operations to remove material from a bank of a mine. On a conventional rope shovel, a dipper is attached to a handle, and the dipper is supported by a cable, or rope, that passes over a boom sheave. The rope is secured to a bail that is pivotably coupled to the dipper. The handle is moved along a saddle block to maneuver a position of the dipper. During a hoist phase, the rope is reeled in by a winch in a base of the machine, lifting the dipper upward through the bank and liberating the material to be dug.
To release the material disposed within the dipper, a dipper door is pivotally coupled to the dipper. When not latched to the dipper, the dipper door pivots away from a bottom of the dipper, thereby freeing the material out through a bottom of the dipper. Current shovels use a dipper door trip mechanism to unlatch and release the dipper door from the dipper. The dipper door trip mechanism includes a latch bar that is moved in and out of an opening in a latch keeper on the dipper. Movement of the latch bar generates significant amounts of friction and wear on surfaces of the latch bar and latch keeper as the latch bar slides in and out of the latch keeper. Thus, current dipper door trip mechanisms employ use of expensive, exotic, high strength materials on the latch bar and/or latch keeper to try and withstand some of the high amounts of friction and wear.